This invention relates to simulation testing of an anti-block system and more particularly to an apparatus and a method for simulation testing of an anti-block system as utilized in an automobile.
Automobiles are currently being produced with anti-block or anti-skid systems to control skidding. Such an anti-block system typically includes a rotary movement-electrical signal transducer subsystem associated with each wheel of the automobile, a computer controller, and an electrical signal-brake pressure transducer subsystem associated with each brake of the automobile. Each rotary movement-electrical signal transducer subsystem supplies an electrical signal which is in pulses frequency-related to the rotary movement of its associated wheel. These signals are read and interpreted by a processor-controller, which, when a skid is indicated signals the electrical signal-brake pressure transducer subsystems to appropriately adjust brake pressure and thereby block or reduce braking of the skidding wheels.
In at least one such system, as manufactured and sold by Robert Bosch GmbH, the processor-controller generates a pressure release signal when the frequency of the input signal from a wheel drops below and is decreasing from the frequency of the input signal from the other wheels. The computer controller also generates a pressure hold signal when the frequency is low but increasing. With a rear wheel, the pressure release and pressure hold signals are of relative long duration. With the front wheels, however, these signals are so brief as to be make accurate measurement of their magnitude practically impossible.
In the past, testing of the Bosch controller has been conducted by electronically simulating simultaneous skidding of all four automobile wheels. Since simulation of this situation may not accurately reveal front-wheel responsiveness, a better test has long been sought.